How To Drain Gas From Your Lawn Mower

Draining gas from a lawn mower is a critical maintenance strategy to keep the engine in its prime condition. This practice is almost unavoidable when storing the mower after the mowing season.

But how do you drain gas from your lawn mower safely and effectively? Read on as we discuss various ways to siphon gas from a lawn mower. We’ll also look at the reasons why you should drain the gas.

How To Siphon Gas From a Lawn Mower

Before you can siphon gas, ensure to prepare your lawn mower. With adequate preparation, you can drain all the gas that may wreck your mower if left in the tank.

Below are steps to follow when siphoning gas from the mower.

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Add a Fuel Stabilizer

Adding a fuel stabilizer to the fuel tank keeps the gasoline fresh and effective for an extended period. The stabilizer has additives that treat fuel, preventing it from breaking down and forming gummy deposits.

Once treated, the fuel will ignite your engine properly in the next mowing season. Note that fuel stabilizers won’t restore the efficacy of your gas if it’s old or deteriorated. It only works with fresh fuel to extend its life.

You should add a fuel stabilizer before draining gas to ensure the gasoline left in the system doesn’t hurt the engine.

After adding the stabilizer, run the engine for around 10 minutes. This process allows the stabilizer to mix with fuel and circulate through the fuel system.

Allow the Engine To Cool Down on a Flat Surface

Whether it’s a push or ride-on mower, placing it on a level surface is essential. The surface could be your driveway, patio, or any other flat area in your yard. The primary reason is to prevent oil in the reservoir from running out and covering parts of the motor.

If you’re operating a ride-on mower, engage the parking brake and turn the engine off. You can also remove the ignition key to ensure it doesn’t start up accidentally.

The best way to siphon gas from a push mower is by placing it on a flat elevated surface. Lift the mower and put it on a bench or two sawhorses. This will allow the drain container to be lower than the mower for gravity to work. Allow the engine to cool down before draining the gas.

Disconnect the Spark Plug

Another way to prevent the mower’s engine from accidentally turning on is by disconnecting the spark plug. It’s also a great way to avoid potential hazards when siphoning gas. Gas is highly combustible, and a spark from the plug can cause an explosion.

Start by disconnecting the wire connected to the plug. You’ll find this wire attached to the pug with a spring clip. In most cases, you can easily detach it with your fingers. After disconnecting the wire, pull the spark plug to avoid accidental sparking.

Methods of Siphoning Gas

Your lawn mower is now ready for draining gas. To get the job done effectively, you need to choose the correct method of siphoning gas.

Below are three different techniques you can use.

Increasing the Internal Air Pressure

If you prefer this method, find a transparent hose and cut it into two lengths. One hose should be longer, while the other should be smaller.

Then, place your drain can near the mower. Place the drain container lower than the mower’s fuel tank to ensure smooth gas flow.

Insert one end of the longer hose into the bottom of the tank and place the other end into the drain can. Next, feed the shorter hose into the tank, ensuring it doesn’t touch the fuel.

Seal the fuel cap where the two hoses get into the fuel tank. You can seal the connection using an old, wet rag or towel. The seal prevents air from escaping the tank.

After sealing the cap, blow air into the smaller tube to increase the air pressure in the tank. You can do this with your mouth, air pump, or a compressor.

Keep blowing more air into the tank until gas flows through the longer hose. If you’re siphoning old or deteriorated gas, avoid inhaling the fumes as you blow the air. You can stop blowing once the flow becomes continuous.

Use a Siphon Pump

You can use a siphon pump if you’re looking for a more straightforward gas-draining method. These pumps can be automatic or manual.

Siphon pumps have transparent tubing and a pump. You’ll use the pump to apply the initial suction needed for the gas to start flowing.

Since siphon pumps come with two different ends, knowing where each end should go is essential. Insert the brass end of the hose into the tank and ensure it gets to the bottom. Put the other end into your drain can.

Squeeze the pump or flip the switch depending on the type of siphon pump. This will apply suction and cause the gas to flow.

Siphon Pump
Siphon Pump

Suction Method

This method works in emergencies or when you’re uncomfortable with the other options. In this case, you need long transparent tubing. Feed one end into the fuel tank and ensure it sits at the bottom.

Place the other end into your mouth and create the required suction in the tube. Pay attention to the flow of fuel in the hose. You don’t want it to get into your mouth.

Hold the tube near your mouth, ready to compress it once the liquid is a few inches from the hand. Remove the hose from your mouth and stick the free end into the drain can. Release the crimp for gas to flow from the tank to the drain can.

Siphoning Gas with No Mess

Other Ways to Drain Gas From Your Lawn Mower

Below are other ways of draining gas from a lawn mower.

Disconnect the Carburetor and Open the Drain Tube

After siphoning gas from the tank, some can be left in the fuel system. You can drain this gas by disconnecting the carburetor and opening the drain tube.

Locate the fuel line behind the air filter and detach it. Most lawnmowers feature a drain plug connected to the carburetor, while others have a drain tube at the tank’s base. Open the drain tube and allow the remaining gas to flow into your drain can.

Run the Mower Continually

An alternative method to draining the remaining gas from the fuel system is running the mower continually. Before starting up the engine, remove the tube you inserted when siphoning and close the tank.

Pick the drain can, close it, and preserve it. If the gas is old or deteriorated, you can keep the drain tank safe for disposal.

Next, reattach the spark plug, reconnect the wire, and insert the ignition key if your mower has one. Turn on the ignition and take your mower out in the yard. Allow the engine to run until it dies out. Once this is done, your mower will have drained all the gas in the fuel system.

Pumping or Turkey Baster

If the gasoline in your mower’s fuel system has gone bad, you can’t run the engine to get rid of it. So, what should you do if you don’t have access to tubing or a siphon pump?

In this case, a pumping or turkey baster method can be an effective solution. A turkey baster in your kitchen will do the trick.

Squeeze the bulb to create suction and insert the baster into the fuel tank. Release the bulb to fill the baster with gasoline. Remove the baster from the tank and drain the gas in a container. Repeat the process to ensure you drain all the gas in the tank.

turkey baster
Turkey baster

Why Drain Gas From a Mower?

Here are the reasons for draining gas from a mower.

Clear Out the Fuel Tank of Sludge and Particles

Sludge and particles can accumulate in your mower’s fuel tank over time. They form when dirt, debris, rust, and oxidized fuel build up in the tank. When sludge and particle buildup spread in the fuel system, they can cause significant damage to your mower.

Draining the gas from your mower removes all the sludge and particles. This works best when you disconnect the carburetor and open the drain tube to clear the remaining gas in the system. After removing these components, your engine will start running better.

Fuel Line Inspection

Draining gas from your mower allows you to inspect the fuel line for defects. Some of the things you’ll want to check out for include leaks and wear.

It’s easy to notice signs of wear or leak in the gas tank when inserting the tubes. You can also check for wear or leaks when disconnecting the drain tube or plug. Consider replacing a leaking fuel line.

Replacing a fuel line with a few cracks that are not leaking is also advisable.

Ready for Winter Storage

When prepping your mower for winter storage, you’ll want to drain the existing gas. The mower will sit in your garage for months, so the gas can deteriorate and wreck it.

Gasoline has volatile compounds that make it combustible. When you store your mower with gas, the volatile compounds tend to evaporate. This process causes the gas to break down and form gummy deposits in the fuel system.

When you run the mower, the old fuel circulates these deposits and clogs the fuel system. The deposits cause the engine to sputter, hesitate, or fail to start. Always drain gas from the fuel system before storing your mower in winter.

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